Location

The picture was taken on October 3, 2019, in Les Vegas, Nevada. The image is of a Joshua tree growing in a desert.

Observations

The area captured in the photo is a part of the Mojave desert. As observed, the region is rich in unique vegetation that is particularly adapted to arid climates. Some of the species common in the area surrounding Las Vegas are succulents like aloe vera, trees, grasses, and cacti. The growth rate of the cactus plants differs, with some growing to greater heights than the others (Zemon). Cactus plants are particularly famous for their ability to survive in any dry area, places where no other flora can thrive. The ground is covered by shrubs and grasses with a mountain clearly visible in the background. The shrubs are most likely creosote bushes (Larrea tridentata), common to the Mojave Desert. The grasses are harder to identify. The center of the picture is occupied by the Joshua tree also known Yucca brevifolia or yukka palm. The plant is closely associated with Mojave desert to the point where it inspired the naming of a national park.

Interpretation

Cacti plants are mainly native to South and North America. There are, however, some exceptional species that have been spotted in Tropical Africa and Sri Lanka. The plant is believed to have emerged 30 million years ago; however, it evolved into a new species after the continental drift (Zemon). This circumstance explains why cacti are rare on some continents and present in others.

            Cactus plant has unique plant features to enable it to survive in the drylands. Deserts and semi-desert regions receive minimal rainwater. As such, plants growing in such regions have to adapt to the dry environment (Mackenzie). The body and stem of cactus swell in periods when there is sufficient moisture to store water for the plant. In times of drought, the body shrinks following the use of the stored water in the process of photosynthesis.

The most significant adaptation for survival in dry regions is the cactus spines. These are modified leaves that help the plant adapt to extreme weather conditions. It is observed that regular leaves have a high surface area which would cause excessive loss of water through transpiration (Mackenzie). Cactus plant reduces the surface area by modifying the leaves into spines. These spines are also beneficial in the collection of moisture from the environment that is dripped back into the country for survival. Additionally, the spines are important in warding off predators from the plant, contributing further to its longevity.

Living in the arid and semi-arid areas also contributes to the survival of the cactus plants. Since such areas receive minimal rain, other plants cannot thrive in the region. As a result, cacti face no competition for the nutrients on the ground (Zemon). In instances that the weather and the environment become extremely harsh for the plant, they are likely to become dormant and start thriving when favorable conditions ensue. Cacti plants are highly adaptive which enables them to endure different environmental conditions.  Joshua Trees share many of the adaptations to the environment that cacti have. Their leaves are long and narrow, resembling needles or daggers. They have complex and extensive roots to collect moisture more efficiently. They strive in grasslands as shown in the picture.